This invention relates in general to an apparatus for coupling and controlling the overall operation of the various components of a heat pump system. In particular, this invention relates to an improved low voltage heat pump control panel having a single master switching relay through which all of the heating and cooling components of a heat pump system can be coupled, controlled and tested.
A typical heat pump heating and cooling system includes an indoor thermostat which monitors the temperature of the environment which is being controlled, an outdoor unit which is comprised of a heat pump operable to heat and cool the environment being controlled, and an indoor unit which is comprised of secondary heaters operable to supplement the heating capacity of the outdoor heat pump.
The heating efficiency of a heat pump is directly related to the outdoor temperature. In other words, the heating capacity of a heat pump decreases as the outdoor temperature drops. Since the heating capacity of a heat pump is temperature dependent and since the heating load in most areas is greater than the normal cooling load, the indoor unit is normally equipped with secondary heaters to supplement the heating capacity of the outdoor heat pump. In many cases, the outdoor unit is equipped with one or more thermostats which are operable to monitor the outdoor temperature and to inhibit the heating operation of the indoor unit if the heating capacity of the heat pump at the particular outdoor temperature is sufficient to meet the heating demand.
The proper interaction of the above-described components is essential to the efficient operation of the overall system. Additionally, the heating and cooling components of the heat pump system must be properly connected so that the outdoor unit can be effectively removed from the system if problems with the outdoor heat pump develop. Finally, it is desirable to interconnect all of the heating and cooling components of the system in a central apparatus which is of a standard design and can be used in a number of heat pump systems.
My invention provides a low voltage heat pump control panel that is of a standard design and suitable for use in a number of different heat pump systems. The low voltage control panel of the present invention utilizes a single master switching relay which controls the overall operation of the heat pump system and provides a central location from which all of the heating and cooling functions of the system can be tested. Furthermore, the master switching relay is removable and may be replaced by a suitable plug from a remote control testing unit which is operable to remotely initiate all of the heating and cooling functions of the system. The heating and cooling functions which can be initiated in this manner include the heating operation of the heat pump, the cooling operation of the heat pump, the operation of the indoor fan, the operation of each secondary heater, and any combination of the above-mentioned operations. The remote control unit is provided with a number of switches which correspond to the various heating and cooling operations of the system. Closure of a particular switch connects the relay input to which this switch is connected and initiates the corresponding heating or cooling operation controlled by this switch.
My invention also includes an emergency heat switch which controls the switching state of the master switching relay. Closure of the emergency heat switch causes the master switching relay to switch states, thereby placing the system in the emergency heat mode. In the emergency heat mode, the outgoing unit is effectively removed from the system and all of the heating of the system is provided by the secondary heaters of the indoor unit. Finally, the low voltage control panel of the present invention is equipped with time delay relays which are operable to stagger the start of the secondary heating units to eliminate the possibility of an electrical power surge.
It is therefore an object of the present invention to provide an apparatus for effectively interconnecting the low voltage control sections of the heating and cooling components of a heat pump system.
Another object of the present invention is to provide an apparatus for effectively interconnecting the low voltage control sections of the heating and cooling components of a heat pump system that is of a standard design and can be used in a number of different heat pump systems.
It is an aim of the present invention to provide an apparatus for effectively interconnecting the low voltage control sections of the heating and cooling components of a heat pump system that can control the overall operation of the system.
Also an objective of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuit of the heating and cooling components of a heat pump system whereby all of the heating and cooling operations of the system can be tested from a central location.
A further object of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuit of the heating and cooling components of a heat pump system wherein servicing and testing of the heat pump system can be greatly facilitated by providing a central location from which all of the operating functions of the system can be remotely initiated.
Still another one of the objects of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuits of the heating and cooling components of a heat pump system that uses a single master switching relay having two switching states and being operable to control the overall operation of the system.
Another aim of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuits of the heating and cooling components of a heat pump system that includes a single master switching relay which may be removed from the system and replaced by a plug from a remote control testing unit.
A further object of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuit of the heating and cooling components of a heat pump system wherein the heating and cooling functions of the system can be remotely initiated by a remote control testing unit.
It is also an object of the present invention to provide an apparatus for effectively interconnecting the low voltage control circuits of the heating and cooling components of a heat pump system that includes an emergency heat switch which is operable to control the switching states of the master switching relay.
An important objective of the present invention is to provide an apparatus for effectively interconnecting the low voltage control circuits of the heating and cooling components of a heat pump system that includes time delay relays which are operable to delay the start of the secondary heaters of the indoor unit.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description of the drawings.